無法在Cygwin上安裝libv8 gem

Question

如何安裝libv8 gem？ 我無法安裝libv8 gem。 當我嘗試時，我得到以下錯誤。

$ gem install libv8
Building native extensions.  This could take a while...
ERROR:  Error installing libv8:
        ERROR: Failed to build gem native extension.

        /usr/bin/ruby.exe extconf.rb
creating Makefile
Using compiler: /usr/bin/g++
which: no gmake in (/usr/local/bin:/usr/bin:/cygdrive/c/WINDOWS/system32:/cygdrive/c/WINDOWS:/cygdrive/c/WINDOWS/System32/Wbem:/cygdrive/c/WINDOWS/system32/WindowsPowerShell/v1.0:/cygdrive/c/Program Files/Microsoft SQL Server/100/Tools/Binn/VSShell/Common7/IDE:/cygdrive/c/Program Files/Microsoft SQL Server/100/Tools/Binn:/cygdrive/c/Program Files/Microsoft SQL Server/100/DTS/Binn:/cygdrive/c/Program Files/Heroku/bin:/cygdrive/c/Program Files/ruby-1.9.2/bin:/cygdrive/c/Program Files/git/bin:/cygdrive/c/Program Files/git/cmd:/cygdrive/c/Program Files/DTN/IQFeed:/cygdrive/c/Program Files/OpenVPN/bin:/cygdrive/c/Program Files/Java/apache-ant-1.8.3/bin:/usr/lib/lapack:/cygdrive/c/Program Files/Notepad++:.:/cygdrive/c/Program Files/Java/android-sdk/platform-tools/:/cygdrive/c/Program Files/Java/android-sdk/tools/:/cygdrive/c/Program Files/Java/jdk1.7.0_03/bin)
In file included from ../src/conversions-inl.h:42:0,
                 from ../src/conversions.cc:32:
../src/platform.h:77:12: error: new declaration ‘int random()’
/usr/include/cygwin/stdlib.h:29:6: error: ambiguates old declaration ‘long int random()’
make[1]: *** [/usr/lib/ruby/gems/1.9.1/gems/libv8-3.11.8.13/vendor/v8/out/ia32.release/obj.target/preparser_lib/src/conversions.o] Error 1

我試着用

$ gem install libv8 --pre
Fetching: libv8-3.5.10.beta1.gem (100%)
Building native extensions.  This could take a while...
Successfully installed libv8-3.5.10.beta1
1 gem installed

但bundle install仍然無法運行。 它仍然試圖安裝版本3.11.8.13。

Installing libv8 (3.11.8.13) with native extensions
Gem::Installer::ExtensionBuildError: ERROR: Failed to build gem native extension.

libv8 gem不在我的Gemfile中。 我不知道如何找出嘗試使用它的內容，但在搜索時我發現rubyracer使用的是libv8而我確實有

group :assets do
  gem 'therubyracer', :platform => :ruby

我甚至嘗試編輯/usr/lib/ruby/gems/1.9.1/gems/libv8-3.11.8.13/src/platform.h文件並注釋掉第77行：

//int random();

但是當我運行gem install libv8 ，它覆蓋了我的更改並仍然出錯。 我在gem install libv8 --help看到了一個技巧，所以我再次編輯了該文件並注釋掉了第77行，並嘗試了

cd /usr/lib/ruby/gems/1.9.1/gems/libv8-3.11.8.13/vendor/v8
make

但是，這只是給出了不同的錯誤：

In file included from /usr/lib/gcc/i686-pc-cygwin/4.5.3/../../../../include/w32api/winsock2.h:56:0,
                 from ../src/win32-headers.h:77,
                 from ../src/platform-win32.cc:31:
/usr/lib/gcc/i686-pc-cygwin/4.5.3/../../../../include/w32api/psdk_inc/_fd_types.h:100:2: warning: #warning "fd_set and associated macros have been defined in sys/types.      This can cause runtime problems with W32 sockets"
In file included from ../src/win32-headers.h:80:0,
                 from ../src/platform-win32.cc:31:
/usr/lib/gcc/i686-pc-cygwin/4.5.3/../../../../include/w32api/wspiapi.h:26:41: error: expected ‘>’ before numeric constant
../src/platform-win32.cc: In function ‘int random()’:
../src/platform-win32.cc:122:12: error: new declaration ‘int random()’
/usr/include/cygwin/stdlib.h:29:6: error: ambiguates old declaration ‘long int random()’

Answer 1

對於那些只想讓錯誤消失的人來說，我覺得應該有一個答案，這樣他們就可以繼續學習。

看來你不需要'therubyracer'專門 - 你可以選擇其他一些javascript引擎。

具體來說，打開文件Gemfile ，並將'therubyracer'更改為'therubyrhino'。 （如果rhino不起作用，還有更多選項和建議： https ： //github.com/sstephenson/execjs#readme

Answer 2

由於您的問題提到了Cygwin，我假設您是Windows用戶。 目前，沒有辦法在Windows中安裝therubyracer或libv8，如其維護者所說： windows上的therubyracer gem 。 不幸的是，Windows不是Rails。

如果你確實需要libv8，你可以嘗試使用nodejs。 它帶有一個二進制，方便所有平台。

Answer 3

我剛剛在Win7開發機上遇到了同樣的問題。 它看起來像是安裝https://github.com/hiranpeiris/therubyracer_for_windows並在Gemfile添加gem 'therubyracer'來排序。

之前：

$ rails generate
c:/Ruby193/lib/ruby/gems/1.9.1/gems/execjs-1.4.0/lib/execjs/runtimes.rb:51:in `autodetect': Could not find a JavaScript runtime. See https://github.com/sstephenson/execjs for a list of available runtimes. (ExecJS::RuntimeUnavailable)
    from c:/Ruby193/lib/ruby/gems/1.9.1/gems/execjs-1.4.0/lib/execjs.rb:5:in `<module:ExecJS>'
(...)

這基本上意味着Rails需要rubyracer ，因此需要libv8 。

后：

$ rails generate
    SECURITY WARNING: No secret option provided to Rack::Session::Cookie.
    This poses a security threat. It is strongly recommended that you
    provide a secret to prevent exploits that may be possible from crafted
    cookies. This will not be supported in future versions of Rack, and
    future versions will even invalidate your existing user cookies.

    Called from: c:/Ruby193/lib/ruby/gems/1.9.1/gems/actionpack-3.2.8/lib/action_dispatch/middleware/session/abstract_store.rb:28:in `initialize'.

Usage: rails generate GENERATOR [args] [options]
(...)